Why Doesn't My Code Work?: Returning Complex Values In Swift Functions

Hi Nate,

There are a few things wrong with your code, but you're actually pretty close.

1. When you declare a function, you only specify the return type - you're trying to declare variables at the same time. Change the return to (Double, Double), since that's the type: a tuple with two Doubles.
2. Now we need to declare the constants lat and lon inside the function (e.g. let lat: Double)
3. In your switch statements, you've got a bunch of extraneous colons. What you should be doing is for each case, setting the value of the constants lat and lon. For example, case "Eiffel Tower" : [new line] lat = 48.8582 [new line] lon = 2.2945
4. The instructions tell you what to return in the default case. If you don't follow those instructions, you'll also get a compiler error, because you're trying to use values that may not have been initialized in the return statement.

I'm not going to post a full solution, because I think you'll benefit from making the fixes on your own. Post back here when you've gotten it to work!

Cheers

-Greg

Thanks so much! Your answer helped me out a bunch:) Heres what I have....

func getTowerCoordinates(location: String) -> (lat: Double, lon: Double) {

    var lat: Double = 0.0, lon: Double = 0.0

    switch location {
    case "Eiffel Tower": lat = 48.8582; lon = 2.2945
    case "Great Pyramid": lat = 29.9792; lon = 31.1344
    case "Sydney Opera House": lat = 33.8587;  lon = 151.2140
    default: return (0,0)
    }

    return (lat, lon)
}

I was on this problem for a few days, on and off and couldn't do it, this is as close as I got, it doesn't look to different to the post above actually?

func getTowerCoordinates(location location: String) -> (Double, Double) {

    let lat: Double
    let lon: Double

    switch location {
    case "Eiffel Tower": let lat = "48.8582"; let lon = "2.2945"
    case "Great Pyramid": let lat = "29.9792"; let lon = "31.1344"
    case "Sydney Opera House": let lat = "33.8587"; let lon = "151.2140"
    default: (0,0)
    }
    return (lat, lon)
}

getTowerCoordinates(location: Eiffel Tower)

I changed it to the following based on the directions in the reply from Greg, but still cannot pass in the value in from outside the function:

func getTowerCoordinates(location location: String) -> (Double, Double) {

    var lat: Double
    var lon: Double

    switch location {
    case "Eiffel Tower":
        var lat = 48.8582
        var lon = 2.2945
    case "Great Pyramid":
        var lat = 29.9792
        var lon = 31.1344
    case "Sydney Opera House":
        var lat = 33.8587
        var lon = 151.2140
    default: (0.00,0.00)
    }
    return (lat, lon)
}

getTowerCoordinates(location: Eiffel Tower)

Hi Greg, many thanks for checking my work!

Initially I didn't have a label on the parameter, I think that after all of the combinations I tried it must have slipped in.

Re-declaring the variables seems ridiculous, I don't know why I did that!

The reason I used "0.0" was because it was a Double, I thought that it would have to have something after the decimal place, unlike Int, I guess I was wrong. I'll remember that about "0", I've been reading over "Initialisation" but it's a little bit of a mind bender for me right now; https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Initialization.html

Understood. Thank you for taking the extra time!

I used quotation marks to pass in the value to the function, but then ran into the error you were referring too: initialisation as the compiler warned me that I was trying to attain a value without it being initialised and the example above gave it away: I needed to initialise the variables "lat" and "lon" when declared inside the function and not it works!